Message294063
I discussed character devices mostly because of the NUL device. It could be surprising that Python dies on an encoding error when output is redirected to NUL:
C:\>chcp 1252
Active code page: 1252
C:\>python -c "print('\u20ac')" > nul
C:\>chcp 437
Active code page: 437
C:\>python -c "print('\u20ac')" > nul
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Program Files\Python36\lib\encodings\cp437.py", line 19, in encode
return codecs.charmap_encode(input,self.errors,encoding_map)[0]
UnicodeEncodeError: 'charmap' codec can't encode character '\u20ac' in position 0:
character maps to <undefined>
Unix has a similar problem:
$ LANG=C python3 -c 'print("\u20ac")' > /dev/null
Traceback (most recent call last):
File "<string>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character '\u20ac' in position 0:
ordinal not in range(128)
Except /dev/null isn't a TTY. Also, it's rare nowadays for the locale encoding in Unix systems to be something other than UTF-8.
It would be useful if we special-cased NUL like we do for the Windows console, but just to make it use the backslashreplace error handler. Unfortunately I don't know how to do that without calling NtQueryObject, for which ObjectNameInformation (1) can't be used because it's undocumented [1]. GetFinalPathNameByHandle also can't be used because it requires file-system devices. As a crude workaround, we could lump together all non-console character devices (i.e. isatty() but not a console). That will affect serial devices, too, but I can't think of a good reason someone would redirect stdout or stderr to a COM port.
[1]: https://msdn.microsoft.com/en-us/library/ff550964 |
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Date |
User |
Action |
Args |
2017-05-21 00:53:24 | eryksun | set | recipients:
+ eryksun, paul.moore, tim.golden, docs@python, zach.ware, steve.dower |
2017-05-21 00:53:24 | eryksun | set | messageid: <1495328004.58.0.171347369672.issue30410@psf.upfronthosting.co.za> |
2017-05-21 00:53:24 | eryksun | link | issue30410 messages |
2017-05-21 00:53:22 | eryksun | create | |
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